I was wondering if there were any download/upload speed limits set by Sonic's OpenVPN server. The reason why is as follows: I'm connecting from a pfSense box and a speed test yields a download speed of around 350 Mbps on average and an upload speed of around 150 Mbps on average. Now, I obviously wasn't going to get full 1 Gbps speeds while running OpenVPN on pfSense, so the "slowdown" isn't the problem. Instead, the issue that I can't quite figure out is why I'm getting asymmetrical OpenVPN speeds on a symmetrical Gigabit connection (pfSense gives me virtually the full 1 Gbps both ways when not running OpenVPN).

I've checked my pfSense config inside out and everything seems to be OK, so asking about the server was the next natural step...

Hopefully someone from Sonic could shed more light on this but in the meantime is there a different VPN you could try to see if you get the discrepancy? Even a different device to test might shed some light. The CPU may be working hard handling all the encryption / decryption but wouldn't necessarily explain the difference.

That was actually a great suggestion for testing purposes (thanks!), but I've unfortunately run into a little problem - I couldn't find any non-ISP VPN service (i.e., ExpressVPN, NordVPN, and what have you) that would by itself give me faster speeds than 350 / 150 Mbps to begin with, so that particular test is a no-go.

I did try testing with a different, and pretty powerful, computer, and the results were still asymmetrical, so no dice there.

PS. Just for reference, and because it includes some important settings for people trying to maximize their OpenVPN speeds, here's a post I made on the Netgate pfSense forums before posting this one: